For the Paella Marinera:
Render the chorizo in the olive oil. Add the mussels, clams, saffron and pimentón and toss together. Add rice and toss; cover with stock. Add the bacalao and let cook at medium heat for 15 minutes. Check the doneness of the rice and taste; adjust seasoning as necessary. Cook for another 5 to 10 minutes, adding stock if necessary. Add the shrimp, calamari, and peas and cook another 5 minutes. Add the butter and fold carefully.
To Assemble and Serve:
Garnish the Paella Marinera with piquillos and serve.